Tunneling machine with power operated poling plates



Feb. 28, 1967 J. R. TABOR 3,306,055

TUNNELING MACHINE WITH POWER OPERATED POLING PLATES Filed June 10, 1964 3 Sheets-Sheet l r-r-I INVENTOR. JoH/v 7450/2 lwbzYm Ffib. 28, J. R. TABOR TUNNELING MACHINE WITH POWER OPERATED POLING PLATES Filed June 10, 1964 6 Sheets-Sheet 2 INVENTOR. JOHN E. 72750 AM, W? W J. R. TABOR Feb. 28, 1967 TUNNELING MACHINE WITH POWER OPERATED POLING PLATES 3 Sheets-Sheet 3 Filed June 10, 1964 PUMP INVENTOR. JoH/v 1? 77950&

ATTORNEY/ United States Patent 3,s0s,ess TUNNELING MAQHINE WITH PQWER ()PERATED POLING PLATES John R. Tabor, 3400 Spruce St., Racine, Wis. 53403 Fiied June 10, 1964, Ser. No. 374,004 9 Claims. (Cl. 6185) This invention relates to a tunneling shield with power operated poling plates.

The tunneling shield of the present invention is provided with extendible poling plates about the shield hood or visor in order to provide greater protection for personnel working in the shield. This is particularly useful when the shield is advanced through relatively loosely packed earth and to protect such personnel from falling earth, rocks and other debris.

In accordance with the present invention there is a series of laterally adjacent poling plates about the hood, each poling plate being individually movable with respect to the hood and each having a power operator such as a fluid motor or the like. A particularly important feature of the invention is the guide means upon which the respective plates are guided in their longitudinal movement with respect to the shield. Guide means are provided both along the medial center line of each poling plate and along the lateral edges thereof, thus to provide positive control and guidance for each plate.

In preferred embodiments of the invention, the lateral edge guide means is formed by relieving facing lateral edges of each plate to form longitudinally extending slots between adjacent plates. The shield is provided with tongues or lugs which project into said slots and have pad heads overlapping the poling plates adjacent said slots. The medial guide means desirably comprises longitudinally extending slots formed in the shield hood, the poling plates being provided with tongues or lugs which project into the shield slots.

The slots at the lateral margins of the plates are desirably longer than the medial slots so that the guide means at the center of the plate will stop forward movement of the plate while the shield lugs remain in the slots between the facing lateral edges of adjacent plates.

The power operated means desirably comprises hydraulic motors, each connected to the leading edge of one of the poling plates which projects beyond the edge of the shield hood. This edge normally inclines forwardly and upwardly. In accordance with the present invention each fluid motor is the same length and has the same forward stroke and has a bracket coupling pivotally connecting it with the shield. These coupling brackets are successively staggered rearwardly from the uppermost poling plate toward the lowermost poling plate complementary to the incline of the forward edge of the hood.

An important feature of the invention relates to the inclination of the hydraulic motors by which they exert both a forward force component on the plates to push the plates forwardly and an upward force component on the plates to oppose the earth overburden and hold the plates against downward deflection when they are extended beyond the edge of the shield. In accordance with the present invention, means are provided to selectively control the pressure in the motors. This pressure is high when the plates are extended to force them through the earth. The pressure is reduced when the entire shield is moved forwardly, thus to maintain a suflicient upward component of force to oppose the earth overburden while still permitting the shield to advance forwardly under the plates.

Other objects, features and advantages of the invention will appear from the following disclosure in which:

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FIGURE 1 is a perspective view of a tunneling shield embodying the present invention, one of the independently movable poling plates being shown fully extended and the others being shown fully retracted.

FIGURE 2 is an enlarged vertical cross section taken through a tunneling shield embodying the present invention, additional details of the tunnel retaining walls being also illustrated.

FIGURE 3 is a fragmentary plan view of a tunneling shield embodying the present invention, extended positions of the poling plates being shown in broken lines.

fFIGURE 4 is a fragmentary inverted plan view there- 0 FIGURE 5 is a fragmentary cross section taken along the line 55 of FIGURE 3.

FIGURE 6 is a fragmentary cross section taken along the line 5-6 of FIGURE 3.

FIGURE 7 is a schematic view illustrating the hydraulic control circuit for the motors.

Although the disclosure hereof is detailed and exact to enable those skilled in the art to practice the invention, the physical embodiments herein disclosed merely exemplify the invention which may be embodied in other specific structure. The scope of the invention is defined in the claims appended hereto.

Except for the provision of the poling plates, the tunnelin shield 10 is conventional. It is provided with a forwardly extending hood 11 having a forward edge 12 which is forwardly and upwardly inclined to form a visor to protect personnel from falling earth, rocks and other debris.

As the tunnel is formed, the shield is pushed forwardly through the earth. Behind the shield support beams 13 are emplaced and wooden lagging 14 is positioned between the beams 13 to shore up the tunnel walls.

The shield 10 is periodically thrust forwardly under pressure of the hydraulic motors 15 which are mounted in the shield ribs 16, 17. Motors 15 have rearwardly projecting pads 18 which bear on the foremost beam 13. The motors 15 concurrently are energized to thrust the shield forwardly.

The hood or visor 11 may have insufiicient extension to adequately protect personnel when the earth is loose or is subject to rock fall, etc. In accordance with the present inevntion, the shield is provided with a series of poling plates 21, 22, 23, 24, 25, 26, 27. These consist of plates curved on the arc of the shield and are placed on the outer surface of the hood 11 and extend about its upper periphery. These plates have relatively sharp forward cutting edges and are adapted to be moved longitudinally of the shield by power means which desirably comprise fluid motors 30. Their range of movement is indicated in full and broken lines in FIGURE 3.

Each poling plate 21-27 is provided on its longitudinal medial center line with a downwardly extending tongue or lug 31 fixed to the plate through bracket pad 32 welded around its periphery to the poling plate, as shown in FIGURE 5. For each plate the hood 11 is provided with a longitudinal slot 33 through which the lug or tongue 31 extends. Lug 31 is provided at its end inside the shield with a pad 34 which overhangs the margin of slot 33. Accordingly, the tongues 31 and grooves 33 guide the plates in their longitudinal movement with respect to the shield hood 11.

The facing lateral edges of adjacent poling plates are relieved slightly at the tail ends of the plates to form slots 35 therebetween. As best shown in FIGURE 6 shield 11 is provided with a series of upstanding lugs or tongues 36 provided within the hood with bracket pads 37 welded to the hood 11. The tongues or lugs 36 extend through slots 35 and are provided at their ends out- 3 side the shield with headed pads 40 which overhang the facing margins of adjacent poling plates. Accordingly, the lateral margins of the poling plates are guided in their longitudinal movement with respect to the hood 11.

Slots 33 are desirably made slightly shorter than slots 35. Accordingly, even when a poling plate is advanced to its extreme forward position, as shown in broken lines in FIGURE 3, tongues 36 and their overhanging pads 40 remain in contact with the lateral edge of the poling plates. By guiding both the center and the lateral edges of the poling plates, lateral stability in poling plate movement is achieved.

The leading ends of the several poling plates 21-27 are provided with inwardly extending bracket couplings 38 to which the respective hydraulic motors 30 are connected on the pivot pins 39. At their opposite ends the motors 30 are provided with coupling brackets 42 which are welded or otherwise connected to the shield. As best shown in FIGURE 2, the shield conventionally has a skirt 43 which reenforces the hood 11. The rear edge of the skirt is welded to the rib 17.

All of the fluid motors 30 are desirably equal in length and have the same throw. Because the forward edge 12 of the hood 11 is upwardly and outwardly inclined, as shown in FIGURE 2, the several couplings 42 are successively staggered rearwardly from the uppermost poling plate 24 toward the lowermost poling plates 21, 27 complementary to the incline of the forward edge 12 of the hood. Accordingly, the brackets 42 for the uppermost motors 30 are attached to skirt 43 and brackets 42 for lowermost motor 30 are attached to rib 17.

Each motor 30 is desirably independently operable so that each poling plate 21-27 is independently adjustable with respect to the hood. Accordingly, local differences in earth formation encountered can be accommodated for by the individual adjustment of the poling plates. If a rock or other hard object is encountered by one poling plate, this will not preclude the action of the other poling plates.

The leading margin of each poling plate is desirably reenforced therebeneath by a stub plate 44, the rear edge of which butts against leading edge 12 of the hood to define the retracted position of the poling plate. The extreme forward position of the poling plate is defined by engagement of lug 31 with the forward end of slot 33 as shown in broken lines in FIGURE 3.

The hydraulic circuit and control apparatus for the motors 30 is illustrated schematically in FIGURE 7. For simplicity in illustration, only two motors 30 are shown. The motors are double acting. Accordingly, each is provided with a fluid line 50 to its forward end and a fluid line 51 to its rear end. Pressure from a pump 52 is selectively applied to the front or rear of the motor pistons 54 through the control valves 53. In the valve positions shown in FIGURE 7, the motors 30 are energized to extend their pistons 54 and hence the poling plates connected thereto. In the conditions shown in FIGURE 7, the lines 50 function as return lines which discharge to the sump 55 through the pipe 56.

If it is desired to retract one or more of the plates, the appropriate valve 53 can be rotated 90 to reverse the connections to the lines 50, 51.

The effective pressure of pump 52 is controlled by the relief valve 57. The effective pressure at the rear of the pistons 54 is controlled by the relief valve 58 which is in a line 59 connected to each motor cylinder 30 through check valves 62.

The pressures at which the valves 57 and 58 should be set will vary considerably depending upon the condition of the earth through which the tunnel is being bored. In any event, when the plates are to be extended, both valves 57, 58 are set at the same relatively high pressure. Accordingly, the rear ends of the cylinders Will be pressurized at that pressure. For any plate that is not to be extended, its valve 53 is set at a neutral position block- 4 ing both lines 50, 51. Check valve 62 to that motor will prevent pressure in the other motors from energizing that motor.

Assume that one or more of the plates are fully extended and it is now desired to push the entire shield forwardly by actuation of the motors 15. Relief valve 58 will now be set to a relatively low pressure. This low pressure is such that will maintain the upward component of force on the plates to oppose the overburden of the earth and hold the plates against downward deflection. However, this pressure will be insufficient to block forward movement of the shield underpressure of motors 15. The shield will slide under the plates which will remain more or less stationary. Pump 52 which is delivering fluid at the higher pressure for which valve 57 is set, will simply bypass hydraulic fluid through check valve 62 to maintain the pressure in the motors 30 at the lower pressure for which relief valve 58 is set. Pistons 54 will move back in the cylinders of motors 30 and return fluid back to sump 55 through check valve 62 and valve 53. Accordingly, the plates will slide with respect to the shield but will be held against bending by the pressure in motors 30. When it is again desired to extend the plates, relief valve 58 is reset at the higher pressure of valve 57. As aforestated, the specific pressures will vary depending upon earth condition, etc. and will be determined empirically.

From the foregoing it is clear that the hydraulic control mechanism is highly important to achieve proper operation. Otherwise it would not be possible to retract the plates with respect to the shield because the overburden would simply bend the plates around the edge of the shield and preclude their retraction. In order to obtain both a forward and upward component of force of the motors 30 on the plates, the inclined position of the motors 30, as shown in the drawings, is also important.

I claim:

1. A tunneling shield having a hood, a series of laterally adjacent poling plates about the hood, power means for individually moving said plates with respect to the hood each of said plates having first guide means at its lateral edges and second guide means along its longitudinal center line for guiding it in its movement with respect to the hood, the facing lateral edges of said poling plates being relieved to form longitudinally extending slots between adjacent plates, said first guide means comprising lugs on said shield projecting into said slots, said shield having longitudinally extending slots aligned on the longitudinal center line of said poling plates, said second guide means comprising lugs on said plates projecting into said slots. 7

2. The tunneling shield of claim 1 in which each of said lugs has a pad head overlapping poling plate portions adjacent said slots.

3. The tunneling shield of claim 1 in which the slots between adjacent poling plates are longer than the slots on the longitudinal center line of the plates whereby said second guide means stops forward movement of its plate while said first guide means remains in its slot.

4. The device of claim 1 in which each said poling plate has a fluid motor for extending the plate beyond the forward edge of the shield, each said motor comprising means for exerting both a forward force component on the plate to push the plate forwardly and an upward force component on the plate to oppose the earth overburden and hold the plate against downward deflection, means for advancing said shield when the plate is extended, and means for selectively controlling the pressure of the motor to impose a high pressure on the plate to force the plate through the earth when it is desired to extend it and to impose a relatively low pressure on the plate when the shield is advanced to permit the shield to slide beneath the plate but still support the earth overburden and prevent downward deflection of the plate.

5. A tunneling shield having a hood, a series of laterally adjacent poling plates about the hood, power means for individually moving said plates with respect to the hood, each of said plates having first guide means at its lateral edges and second guide means along its longitudinal center line for guiding it in its movement with respect to the hood, the facing lateral edges of said poling plates being relieved to form longitudinally extending slots between adjacent plates, said first guide means comprising lugs on said shield projecting into said slots, said shield having longitudinally extending slots aligned on the longitudinal center line of said poling plates, said second guide means comprising lugs on said plates projecting into said slots, said power means comprising a fluid motor for each plate, said hood having a forward edge which inclines upwardly and forwardly, said poling plates having leading portions extending beyond said edge in all positions thereof including fully retracted position, couplings between said leading portions and corresponding ends of said fluid motors, coupling brackets on said shield for corresponding opposite ends of said motors, said coupling brackets being successively staggered rearwardly from the uppermost said poling plate toward the lowermost said poling plate complementary to the incline of the forward edge of the hood.

6. A tunneling shield having a hood, a series of laterally adjacent poling plates about the hood, power means for individually moving said plates with respect to the hood, each of said plates having first guide means at its lateral edges and second guide means along its longitudinal center line for guiding it in its movement with respect to the hood, said power means comprising a fluid motor for each plate, said hood having a forward edge which inclines upwardly and forwardly, said poling plates having leading portions extending beyond said edge in all positions thereof including fully retracted position, couplings between said leading portions and corresponding ends of said fluid motors, coupling brackets on said shield for corresponding opposite ends of said motors, said coupling brackets being successively staggered rearwardly from the uppermost said poling plate toward the lowermost said poling plate complementary to the incline of the forward edge of the hood, each said fluid motor comprising a cylinder having its axis inclined to the direction of movement of the plate whereby to exert a forward force component on the plate to push the plate forwardly and an upward force component on the plate to oppose the earth overburden and hold the plate against downward deflection.

7. An earth tunneling shield having a forward edge and a poling plate extendible beyond said edge, a fluid motor for extending said plate, said motor comprising means for exerting both a forward force component on the plate to push the plate forwardly and an upward force component on the plate to oppose the earth overburden and hold the plate against downward deflection, means for advacing said shield when the plate is extended, and means for selectively controlling the pressure of the motor to impose a high pressure on the plate to force the plate through the earth when it is desired to extend it and to impose a relatively low pressure on the plate when the shield is advanced to permit the shield to slide beneath the plate but still support the earth overburden and prevent downward deflection of the plate.

8. The shield of claim 7 in which the control means includes a relief valve for said fluid motor and which is selectively adjustable as between said high and low pressures.

9. The shield of claim 7 in which the fluid motor comprises a cylinder having its axis inclined to the direction of movement of the plate.

References Cited by the Examiner UNITED STATES PATENTS 91,071 6/1869 Beach 61-85 834,732 10/1906 Japp 6185 1,355,290 10/1920 Updegrafi 6185 2,139,563 12/1938 Russell 61--85 2,196,100 4/1940 Caputo 6185 FOREIGN PATENTS 567,122 1932 Germany. 575,915 1933 Germany.

CHARLES E. OCONNELL, Primary Examiner. JACOB SHAPIRO, Examiner. 

1. A TUNNELING SHIELD HAVING A HOOD, A SERIES OF LATERALLY ADJACENT POLING PLATES ABOUT THE HOOD, POWER MEANS FOR INDIVIDUALLY MOVING SAID PLATES WITH RESPECT TO THE HOOD EACH OF SAID PLATES HAVING FIRST GUIDE MEANS AT ITS LATERAL EDGES AND SECOND GUIDE MEANS ALONG ITS LONGITUDINAL CENTER LINE FOR GUIDING IT IN ITS MOVEMENT WITH RESPECT TO THE HOOD, THE FACING LATERAL EDGES OF SAID POLING PLATES BEING RELIEVED TO FORM LONGITUDINALLY EXTENDING SLOTS BETWEEN ADJACENT PLATES, SAID FIRST GUIDE MEANS COMPRISING LUGS ON SAID SHIELD PROJECTING INTO SAID SLOTS, SAID SHIELD HAVING LONGITUDINALLY EXTENDING SLOTS ALIGNED ON THE LONGITUDINAL CENTER LINE OF SAID POLING PLATES, SAID SECOND GUIDE MEANS COMPRISING LUGS ON SAID PLATES PROJECTING INTO SAID SLOTS. 